SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d658064cbd2b10dfcad4160e061a62c8a620983709b77582615b6620285bfc' 
  AND token = 'ScWvyLTcS2mqsGcVatnf0w1PVOxBCL6fADEc8KEN1Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}